We have recorded our rehearsal on a Zoom R16 and occasional I hear some distortion on the rhythm track, doesn't seem like peak clipping when I zoom in on the wave file. Any idea where to look?

Listen here: https://soundcloud.com/kierbye1/rhythm-0-wav

Strat

It might be due to analog clipping/overload in the stages before digitization or in the A to D chip. You may not be able to see clipping from that stage in the digital waveform view, since the digital wave is not being clipped.

If there is a mic PAD on the unit, try turning that down.

If no Pad control, try moving the mics further back from the sound source and see if it clears up.

If the mics on the unit have plugs to connect, the plugs could need some cleaning due to oxidation at the connection points. Deoxit or equivalent on a pad and wipe the plugs with it, insert immediately a few times to get the good goo inside the jack as well.


--Mac

Sounds like it's from a Strat - correct?

I've experienced static electricity build-up on the Made in Mexico strat that I used to own and I solved it by backing the pickguard with copper foil, when I also shielded the pickup cavities with copper foil.

That sounds a bit like it, from what I remember back in the day. That was a little under 10 years ago when I bought that guitar and had the disappointing static build up and release, ruining some recordings.

Does it always sound like the very short snippet you posted, or does it change at all over time? Mac eludes to the whole signal chain. What exactly is the full signal chain from guitarist-->guitar-->....-->ZoomR16?

Also is that clip that you posted a .wav rendering from the guitar channel alone or is it from the Zoom R16 output mix-down of all of the tracks? I ask this because it also sounds a bit like an open cable that got recorded accidentally.

Interesting! The guitar is a newly bought U.S. tele. I'll try to describe the signal chain to you soon.
the track is recorded from a shure (dynamic) mike in front of the amp, we have used this setup many times without any anomaly. I'm attaching a longer version of the rhythm track where the distortion is heard here and there. I'm eagerly awaiting your comment :-)


https://soundcloud.com/kierbye1/rhythm-1-wav

Strat

I heard it right near the end as the only other point where it was evident. It's really impossible to tell which part of the signal chain this is coming from: guitar--->effects loop perhaps-->amp
or
mic-->direct box perhaps-->zoomR16

I'm afraid without being on-site to diagnose and debug, I won't be of much help. It certainly doesn't appear or sound to be overdriving of the mic, nor clipping of the input stage on the Zoom unit. This sounds like a static build-up/release issue to me.

-Scott

I hear it at 0.11, at 0.15 (harsh) 0.22, 0.27, 0.43 and at 0.47 (harsh), can you hear the same Scott?

Strat

If you did not notice that distortion "in the air" while recording, but only heard it at playback of the recording, Scott's theory is shot.

I assumed that you are savvy enough to have heard anything that sounds like that coming from the guitars and etc. while actually playing, and would have stopped to correct it or at least check it out.


--Mac

I must shamefully admit that it was first when I was trying to add a Little audio cosmetics to the rhythm track that I became aware of the distortion. It is something that has come up during the last two rehearsals and the reason I haven't noticed it while we were all playing is two fold. We play (too) loud and the distortion is intermittent, on some takes it's not there at all?

Strat

That comment supports what I said above in my first answer.

Try the things I suggest up there.

The offending areas do indeed have a sound I've heard before, that is, the analog electronics being pushed into distortions before or in the A to D circuitry.


--Mac

I hope you are able to find the issue. I would think that this sound could be hard to hear in a rock band rehearsal unless you are specifically listening for it. I assume you are close-micing the amplifier because the drums and so forth are so far down in level on the sample you posted.

Something unintentional is certainly going on. The intermittent nature and appearance in the track where its not actually the hot section of the signal is going to make it hard to track down. Time to see if you can isolate it without the pressure of a rehearsal going on, in my opinion.

Thanks all for your suggestions, I sure hope to find out what's going on. I remember back in the day when a transmitting CB radio nearby could breake into the amps circuitry and generate all kinds of strange sounds, but I guess that's not what's going on here :-)


Strat